Beta-crystalline form of ivabradine hydrochloride, a process for its preparation and pharmaceutical compositions containing it

ABSTRACT

β-Crystalline form of ivabradine of formula (I): 
                         
characterised by its powder X-ray diffraction diagram.
 
     Medicinal products containing the same which are useful as bradycardics.

The present invention relates to the β-crystalline form of ivabradine hydrochloride of formula (I), to a process for its preparation and to pharmaceutical compositions containing it.

Ivabradine, and addition salts thereof with a pharmaceutically acceptable acid, and more especially its hydrochloride, have very valuable pharmacological and therapeutic properties, especially bradycardic properties, making those compounds useful in the treatment or prevention of various clinical situations of myocardial ischaemia such as angina pectoris, myocardial infarct and associated rhythm disturbances, and also in various pathologies involving rhythm disturbances, especially supraventricular rhythm disturbances, and in heart failure.

The preparation and therapeutic use of ivabradine and addition salts thereof with a pharmaceutically acceptable acid, and more especially its hydrochloride, have been described in the European patent specification EP 0 534 859.

In view of the pharmaceutical value of this compound, it has been of prime importance to obtain it with excellent purity. It has also been important to be able to synthesise it by means of a process that can readily be converted to the industrial scale, especially in a form that allows rapid filtration and drying. Finally, that form had to be perfectly reproducible, easily formulated and sufficiently stable to allow its storage for long periods without particular requirements for temperature, light or oxygen level.

The patent specification EP 0 534 859 describes a synthesis process for ivabradine and its hydrochloride. However, that document does not specify the conditions for obtaining ivabradine in a form that exhibits those characteristics in a reproducible manner.

The Applicant has now found that a particular salt of ivabradine, the hydrochloride, can be obtained in a crystalline form that is well defined and that exhibits valuable characteristics of stability and processability.

More specifically, the present invention relates to the β-crystalline form of ivabradine hydrochloride, which is characterised by the following powder X-ray diffraction diagram measured using a PANalytical X'Pert Pro diffractometer together with an X'Celerator detector and expressed in terms of ray position (Bragg's angle 2 theta, expressed in degrees), ray height (expressed in counts), ray area (expressed in counts×degrees), ray width at half-height (“FWHM”, expressed in degrees) and interplanar distance d (expressed in Å):

Angle Area 2 theta Height (counts × FWHM Interplanar Ray no. (degrees) (counts) degrees) (degrees) distance (Å) 1 6.8 130 86 0.6691 13.019 2 9.2 6141 507 0.0836 9.613 3 9.7 882 58 0.0669 9.083 4 10.0 875 72 0.0836 8.837 5 11.9 190 19 0.1004 7.433 6 12.2 500 58 0.1171 7.236 7 13.2 224 30 0.1338 6.694 8 13.8 633 52 0.0836 6.419 9 14.3 466 54 0.1171 6.209 10 14.8 926 76 0.0836 5.977 11 15.0 716 94 0.1338 5.887 12 15.7 531 79 0.1506 5.636 13 16.1 121 16 0.1338 5.502 14 16.9 1354 223 0.1673 5.254 15 18.4 5672 562 0.1004 4.824 16 18.8 1328 131 0.1004 4.716 17 19.7 1617 347 0.2175 4.508 18 20.4 296 34 0.1171 4.341 19 20.7 767 51 0.0669 4.286 20 21.3 1419 211 0.1506 4.178 21 21.6 2458 243 0.1004 4.114 22 22.6 1737 258 0.1506 3.937 23 23.0 1467 73 0.0502 3.865 24 23.7 486 128 0.2676 3.751 25 23.9 504 50 0.1004 3.718 26 25.3 4606 304 0.0669 3.513 27 25.7 791 91 0.1171 3.464 28 26.2 458 91 0.2007 3.406 29 26.6 221 44 0.2007 3.352 30 27.4 706 151 0.2175 3.251 31 27.7 208 27 0.1338 3.215 32 28.1 483 40 0.0836 3.176 33 28.8 242 24 0.1004 3.096 34 29.3 450 74 0.1673 3.049 The invention relates also to a process for the preparation of the β-crystalline form of ivabradine hydrochloride, which process is characterised in that a mixture of ivabradine hydrochloride and water or a mixture of ivabradine hydrochloride, isopropanol and water is heated until dissolution is complete and is then progressively cooled until crystallisation is complete, and the crystals formed are collected.

-   -   In the crystallisation process according to the invention it is         possible to use ivabradine hydrochloride obtained by any         process, for example ivabradine hydrochloride obtained by the         preparation process described in patent specification EP 0 534         859.     -   The solution may advantageously be seeded during the cooling         step.

The invention relates also to pharmaceutical compositions comprising as active ingredient the β-crystalline form of ivabradine hydrochloride together with one or more appropriate, inert, non-toxic excipients. Among the pharmaceutical compositions according to the invention, there may be mentioned more especially those that are suitable for oral, parenteral (intravenous or subcutaneous) or nasal administration, tablets or dragées, sublingual tablets, gelatin capsules, lozenges, suppositories, creams, ointments, dermal gels, injectable preparations, drinkable suspensions.

The useful dosage can be varied according to the nature and severity of the disorder, the administration route and the age and weight of the patient. That dosage varies from 1 to 500 mg per day in one or more administrations.

The following Examples illustrate the invention.

The X-ray powder diffraction spectrum was measured under the following experimental conditions:

-   -   PANalytical X'Pert Pro diffractometer, X'Celerator detector,         temperature-regulated chamber,     -   voltage 45 kV, intensity 40 mA,     -   mounting θ-θ,     -   nickel (Kβ) filter,     -   incident-beam and diffracted-beam Soller slit: 0.04 rad,     -   fixed angle of divergence slits: ⅛°,     -   mask: 10 mm,     -   antiscatter slit: ¼°,     -   measurement mode: continuous from 3° to 30°, in increments of         0.017°,     -   measurement time per step: 19.7 s,     -   total time: 4 min 32 s,     -   measurement speed: 0.108°/s,     -   measurement temperature: ambient.

EXAMPLE 1 β-Crystalline Form of Ivabradine Hydrochloride

720 ml of purified water are preheated to 50° C., and then 250 g of ivabradine hydrochloride obtained according to the process described in the patent specification EP 0 534 859 are added in portions, with stirring, and the mixture is heated at 74° C. until dissolution is complete. The resulting clear solution is heated for 2 more hours at 74° C. and is then progressively cooled, first to 40° C., and then to ambient temperature. The solution is subsequently stored at ambient temperature for 2 days, and then the solid suspension is spread out in a thin layer on a crystallisation plate. The excess water is driven off under a gentle current of nitrogen.

The water content of the resulting product, determined by coulometry, is 12.4%, which corresponds to a tetrahydrate.

X-ray Powder Diffraction Diagram:

The X-ray powder diffraction profile (diffraction angles) of the β-form of ivabradine hydrochloride is given by the significant rays collated in the following table:

Angle Area 2 theta Height (counts × FWHM Interplanar Ray no. (degrees) (counts) degrees) (degrees) distance (Å) 1 6.8 130 86 0.6691 13.019 2 9.2 6141 507 0.0836 9.613 3 9.7 882 58 0.0669 9.083 4 10.0 875 72 0.0836 8.837 5 11.9 190 19 0.1004 7.433 6 12.2 500 58 0.1171 7.236 7 13.2 224 30 0.1338 6.694 8 13.8 633 52 0.0836 6.419 9 14.3 466 54 0.1171 6.209 10 14.8 926 76 0.0836 5.977 11 15.0 716 94 0.1338 5.887 12 15.7 531 79 0.1506 5.636 13 16.1 121 16 0.1338 5.502 14 16.9 1354 223 0.1673 5.254 15 18.4 5672 562 0.1004 4.824 16 18.8 1328 131 0.1004 4.716 17 19.7 1617 347 0.2175 4.508 18 20.4 296 34 0.1171 4.341 19 20.7 767 51 0.0669 4.286 20 21.3 1419 211 0.1506 4.178 21 21.6 2458 243 0.1004 4.114 22 22.6 1737 258 0.1506 3.937 23 23.0 1467 73 0.0502 3.865 24 23.7 486 128 0.2676 3.751 25 23.9 504 50 0.1004 3.718 26 25.3 4606 304 0.0669 3.513 27 25.7 791 91 0.1171 3.464 28 26.2 458 91 0.2007 3.406 29 26.6 221 44 0.2007 3.352 30 27.4 706 151 0.2175 3.251 31 27.7 208 27 0.1338 3.215 32 28.1 483 40 0.0836 3.176 33 28.8 242 24 0.1004 3.096 34 29.3 450 74 0.1673 3.049

EXAMPLE 2 Pharmaceutical Composition

Formula for the preparation of 1000 tablets each containing 5 mg of ivabradine base:

Compound of Example 1 5.39 g Maize starch 20 g Anhydrous colloidal silica 0.2 g Mannitol 63.91 g PVP 10 g Magnesium stearate 0.5 g 

1. A β-Crystalline form of ivabradine hydrochloride of formula (I):

having a powder X-ray diffraction diagram exhibiting peaks at 9.2, 18.4, 19.7, 21.6 and 25.3 deg 2 theta.
 2. A β-Crystalline form of ivabradine hydrochloride of formula (I):

having a powder X-ray diffraction diagram exhibiting peaks at 9.2, 9.7, 10.0 and 14.8 deg 2 theta.
 3. A solid pharmaceutical composition comprising as active ingredient the β-crystalline form of ivabradine hydrochloride of claim 1, in combination with one or more pharmaceutically acceptable, inert, non-toxic carriers.
 4. A method for treating a condition selected from angina pectoris, myocardial infarct, and heart failure, such method comprising administering to a human, a therapeutically effective amount of the β-crystalline form of ivabradine hydrochloride of claim
 1. 5. A solid pharmaceutical composition comprising as active ingredient the β-crystalline form of ivabradine hydrochloride of claim 2, in combination with one or more pharmaceutically acceptable, inert, non-toxic carriers.
 6. A method for treating a condition selected from angina pectoris, myocardial infarct, and heart failure, such method comprising administering to a human, a therapeutically effective amount of the β-crystalline form of ivabradine hydrochloride of claim
 2. 